TORONTO -- The Red Sox received an unpleasant surprise Friday afternoon when they learned outfielder J.D. Drew is suffering from a herniated disc (L5 S1) in his back.

Drew has suffered from chronic back pain throughout his career and had a flareup last Sunday at Fenway Park against Toronto. He missed all three games of a series in Baltimore earlier this week, but it was thought he'd be able to return to action Friday night here in the opener of a weekend set against the Blue Jays.

The original lineup had Drew in right field, but he was scratched soon after the clubhouse opened. He was sent to a local hospital for an MRI, where it was learned he had a herniated disc.

"I hoping not," he said of going on the DL "We've got to figure it out, because I don't want to miss any more time. It could be better [Saturday], or it could be better on Sunday. That's the way it's kind of been all along. I thought I was heading in the right direction [Thursday] because I felt better, but now I'm stiff and we're going to try to get it calmed down and get back to baseball activities without going on the DL."

Drew said he felt good Thursday and thought he'd be able to play Friday. On Friday morning he was a little stiff and took a hot bath in attempt to loosen the stiffness. After the bath his back locked up, and Drew said he felt "progressively worse" during the day. He was having difficulty walking through the clubhouse.

"We're going to try to treat it and get it calmed down," he said.

There's no word on how long he'll be sidelined.

The problem is similar to an injury he had earlier in his career with the Cardinals. While in St. Louis, Drew tore the sheath three-quarters of the way around his spine in the same area where he now has the herniated disc. The Red Sox are expecting a full medical report sometime Friday evening.

"I tore that same sheath around my spine when I was in St. Louis," he admitted. "It's similar and could be the herniated disc from the previous injury. We just need to get a better look at it."

In 2001, Drew missed 12 games when he first suffered the injury. He said Friday he remembers how sharp the pain was.

"I literally could barely walk at that time," he said. "Eventually it healed up and got better. I've done it a couple of times this season, including [during the March trip to] Japan. But I didn't seem to do it as bad last Sunday, and for whatever reason my back is really guarding against letting a spasm out. If I sit down and try to relax, when I stand up I get stiff and I can hardly move."